NES multi-cartridge

Here’s a mutlicartridge hack for the original NES that [Callan Brown] put together. He spent some time snooping around the signals on the circuit board seen above until he found the trace that maps the reset signal from the game console. This will be used to cycle through the various games stored on the cart’s memory chip. The ROM images that will be stored on this cartridge are concatenated, then burned to the EPROM. Since the donor cartridge (and the ROMs which were chosen) use memory managment, the hardware can be tricked into reading the ROM from a specific point in the EPROM.

The switching itself is handled by a 74HC161 binary counter chip. The reset signal from the on-board security chip acts as a clock trigger for the counter. Some clever wiring allows the output of the counter to select the starting address for the EPROM. Each time you press the reset button it increments the counter, thereby selecting a different ROM to load. See [Callan] demonstrate the finished hack in the video after the break.

17 thoughts on “NES multi-cartridge”

Not hard to do, use an eeprom that is far larger than the stock one and simply toggle the high address lines to enable new sections. This is really old school stuff we used to do back in the days of the TRS-80 Color Computer and the C-64.

@fartface indeed. I use the same method to do animations on an LED panel where the smallest memory I could find was > 256B, so I used the extra address lines tied to a binary counter to cycle through the memory blocks.

I used something like this when I was a kid. My neighbors brought it back from vietnam back when the nintendo was still fairly new. It was 2 cartridge segments that when put together were the size of a normal cartridge. It was like a top 50 games or something like that. I thought it was the greatest thing in the world.

Thanks for reading everyone. The real point of this project was to make use of the binary counter, obviously the idea of stacking ROM images together isn’t anything to get excited about.

@usedone, that’s a Famicom multicart you had, most likely 52-in-1, attached to a NES converter. If you check my article and scroll down to the first video, you can see a Famicom game and converter on my NES console, it should look familiar!